Fixed cached images not being updated when source image is modified

CHANGELOG.md

@@ -13,6 +13,7 @@
     * Fixed `Undefined method closure::fields()` when getting avatar for user, thanks @Romarain [#2422](https://github.com/getgrav/grav/issues/2422)
     * Grav 1.6: Added `Flex[Class]::getFlexType()` to all flex classes to have the interface for all Flex classes
     * FlexObjects: Remove null values during save
+    * Fix issue with processed images not being updated when existing image is modified
 
 # v1.6.0-rc.4
 ## 03/20/2019

system/src/Grav/Common/Page/Medium/ImageFile.php

@@ -33,13 +33,14 @@ class ImageFile extends Image
     /**
      * This is the same as the Gregwar Image class except this one fires a Grav Event on creation of new cached file
      *
-     * @param string $type    the image type
-     * @param int    $quality the quality (for JPEG)
-     * @param bool   $actual
+     * @param string $type the image type
+     * @param int $quality the quality (for JPEG)
+     * @param bool $actual
+     * @param array $extras
      *
      * @return string
      */
-    public function cacheFile($type = 'jpg', $quality = 80, $actual = false)
+    public function cacheFile($type = 'jpg', $quality = 80, $actual = false, $extras = [])
     {
         if ($type === 'guess') {
             $type = $this->guessType();
@@ -50,7 +51,7 @@ class ImageFile extends Image
         }
 
         // Computes the hash
-        $this->hash = $this->getHash($type, $quality);
+        $this->hash = $this->getHash($type, $quality, $extras);
 
         // Seo friendly image names
         $seofriendly = Grav::instance()['config']->get('system.images.seofriendly', false);
@@ -103,4 +104,42 @@ class ImageFile extends Image
 
         return $this->getFilename($file);
     }
+
+    /**
+     * Gets the hash.
+     * @param string $type
+     * @param int $quality
+     * @param [] $extras
+     * @return null
+     */
+    public function getHash($type = 'guess', $quality = 80, $extras = [])
+    {
+        if (null === $this->hash) {
+            $this->generateHash($type, $quality, $extras);
+        }
+
+        return $this->hash;
+    }
+
+    /**
+     * Generates the hash.
+     * @param string $type
+     * @param int $quality
+     * @param array $extras
+     */
+    public function generateHash($type = 'guess', $quality = 80, $extras = [])
+    {
+        $inputInfos = $this->source->getInfos();
+
+        $datas = array(
+            $inputInfos,
+            $this->serializeOperations(),
+            $type,
+            $quality,
+            $extras
+        );
+
+        $this->hash = sha1(serialize($datas));
+    }
+
 }

system/src/Grav/Common/Page/Medium/ImageMedium.php

@@ -619,7 +619,7 @@ class ImageMedium extends Medium
             $this->image->merge(ImageFile::open($overlay));
         }
 
-        return $this->image->cacheFile($this->format, $this->quality);
+        return $this->image->cacheFile($this->format, $this->quality, false, [$this->get('width'), $this->get('height'), $this->get('modified')]);
     }
 
     /**